Before answering that question, let us remind ourselves what is the idea of the multiverse. The multiverse is the cosmic notion of many universes existing simultaneously. I exist in this one, but maybe not in another ... verse. Which is rather ridiculous given the fact of non locality in quantum physics which states that if I do something here, it happens there.
In all physics, here and now, there is design of connectedness. That means that if something changes here, it changes there ... simple cause and effect. And, multiplied... that should mean that if no matter how many universes there are, they are either the same of slightly different due to matter of the speed of information; but even in saying that... at the quantum level speed is instant or rather time and space don't really exist in the way we experience them.
If we were to play the game of telephone, we can experience a change in the transmission of information but what does not change is the experience of receiving information that is believed to be true. So, in that case... what was sent is just as true as what was received.
There are those that argue that if you can imagine your life this way or that way then there are just as many different you (s) so to speak. But, even if you can imagine your life in a hundred or thousand different ways, there is only one wave function collapse and it is the one you are aware of. The others are just possibilities and there they will remain and even diffuse into the twilight of the true wave function collapse. Think of a Japanese fan that spreads out in your hand. All are fan tails appear to be equal in shape/color and function; and, all appear connected. Yet all are not the center of the fan nor the hand that holds the fan.
Does that mean that every fan tail is different from the center and different from the hand that holds it all together. No. Is the entire fan the multiverse? Maybe yes and rather no. Yes, as it is a multiple of the same thing and no for the same reason.... none are really different from the other.
So, why make a study of the multiverse when you need only to study the first fan and better to study the hand that holds the entire fan together.
"For in Him all things were created, things in heaven and on earth,
visible and invisible, whether thrones or dominions or rulers or
authorities. All things were created through Him and for Him. He is before all things, and in Him all things hold together. And
He is the head of the body, the church; He is the beginning and
firstborn from among the dead, so that in all things He may have
preeminence.… Colossians 1:16-18.